Hi,
Keith Whaley wrote:
Peter J. Alling wrote:
Which version K mount, original, M, A, F, FA or extra crispy?
Let's suppose the K-mount is the SMC Pentax 50mm f/1.4.
That design is the first K-mount offerring in that specification, which showed up before the M, A, F or any later K-mount lens, and as close as you can get to the last of the M42 screw mounts.
In which case there is _essentially_ no difference.
By essentially, I mean the K has the same number of lens elements, in the same design as the M-42 which preceded it.
The last 1.4 SMC Takumar was made in 1975, the first 1.4 SMC Pentax K-mount came out in '75.
The Tak has a minimum aperture of f/22, the K is f/16.
The Tak has a smaller filter ring (49mm) while the K has a larger one (52mm.)
So, are they the same lens, in detail? No. Same lens design ~ apparently so.
They ought to perform identically.
Is that what you had in mind when you asked the question?
keith whaley
Rebekah Gonzalez wrote:
okie dokie, say i have two lenses, both are made by pentax, both are 50mm
1.4, one is screw mount and the other is k mount.
hypothetical situation in place, is there any difference other than the
shape of the mount?
If you are thinking of changing mounts, you are not in luck. The diaphragm closing mechanism is different and not (easily) changeable. This will render open-aperture metering unworkable, for one thing. You could remove the stop-down mechanism, use it as a non-metering lens and use an external meter.
mike
